MTHFR Support for Thyroid

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Find out how to provide MTHFR support for thyroid patients through gene testing, diet, and supplements.

Gene testing is giving both patients and providers very useful information to help them get their best health.  One very important gene that can help or hurt our health affects a critical enzyme in our bodies called MTHFR.  

Yet, not all health professionals agree, as demonstrated in a recent post,  that gene testing is helpful.  That is why we took a deep dive into the research to help you decide whether genetic testing for MTHFR is for you and your clients. 

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While genes are important, they aren’t our patients’ destiny.  The field of epigenetics shows how WHAT we eat controls how genes are expressed. 

Knowing our gene risks is an empowering tool for your clients to get the best health possible, and to modify their gene expression.  We hope this overview is a powerful tool for helping to optimize your patient’s health. 

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What is MTHFR?

Methyl tetrahydrofolate reductase (MTHFR) is an enzyme that works as a catalyst for important biochemical reactions in the body.  The MTHFR enzyme converts vitamin B9 (folate) into methyl-folate which is essential for the methylation process. 

Another important task of methylation is turning the amino acid homocysteine into methionine

Excess Homocysteine Damages Cells and Causes Inflammation 

Homocysteine is an amino acid in the body that makes body proteins. Usually, vitamin B12, B6, and folate can break down homocysteine into substances used by the body [R].

Usually, levels of homocysteine in the blood are low. However, in some individuals levels become elevated leading to hyperhomocysteinemia.

Hyperhomocysteinemia causes epithelial cell injury and inflammation. It leads to the following conditions:

Causes of High Homocysteine

Hyperhomocysteinemia occurs for various reasons including:

  • Folate deficiency
  • B6 deficiency
  • B12 deficiency 
  • Kidney disease 
  • Low levels of thyroid hormones (hypothyroidism
  • Medications 
  • Psoriasis
  • Systemic lupus erythematosus 
  • Methylenetetrahydrofolate reductase (MTHFR) genetic mutations 

High homocysteine levels can result from many causes. They often are interconnected. Let’s explore that in more detail. 

Vitamins & MTHFR Change Homocysteine Into Anti-Inflammatory Methionine

Methionine is an essential amino acid. The body cannot synthesize methionine. So methionine must be obtained through diet. Methionine helps with growth and tissue repair. It is also needed for detoxifying processes. Methionine protects cells from pollutants, slows cell aging, and absorbs nutrients like selenium and zinc 

Methionine rids the body of heavy metals such as lead and mercury. It also prevents excess fat buildup in the liver.

Homocysteine is also converted into methionine. 

This process of turning an inflammatory amino acid into an essential amino acid, in effect, reduces heart disease risk

Methionine lowers homocysteine levels showing their relationship to be symbiotic.

Transmethylation, Remethylation, Transsulphuration, & Regulation of Homocysteine

The ability to make methionine is complex. First, we will break down transmethylation for you. 


Transmethylation is the transfer of a methyl group from one compound to another. It is also how homocysteine becomes methionine

It starts with a transfer of a methyl group from the reaction of methionine with the energy-carrying molecule adenosine triphosphate (ATP).

The enzyme methionine adenosyltransferase (MAT) activates the start of transmethylation. It results in the formation of S-Adenosyl-L-methionine (AdoMet or SAM).

After donating the methyl group to acceptor molecules such as DNA,  AdoMet forms the compound S-Adenosyl homocysteine (SAH). S-adenosylhomocysteine hydrolase will then turn SAH into homocysteine.

The enzyme AdoHcy hydrolase (SAHH) breaks down S-adenosylhomocysteine into adenosine and homocysteine. To prevent AdoHyc accumulation both homocysteine and adenosine need to be metabolized and transported out of the cell.


Remethylation is the next step to form methionine. A methyl group from 5-N-methyl tetrahydrofolate (folate or B9) moves to homocysteine. This group also remethylates it back into methionine. The enzyme methionine synthase facilitates this action. It is also dependent on adequate B12 levels to activate the reaction.

This remethylation occurs due to the enzyme methionine synthase (MTR) only if there are folate and B12 present. The methyl group from 5-N-methyl tetrahydrofolate (folate or B9) moves to homocysteine. It will recreate methionine. 


Transsulfuration is another way homocysteine breaks down. Homocysteine combines with serine to form cysteine. Two vitamin B6-dependent enzymes activate transsulfuration: 

  • Cystathionine β-synthase (CBS)
  • Cystathionine γ-lyase (CTH) 

CBS turns homocysteine and serine to cystathionine. CTH breaks down cystathionine to cysteine.

Cysteine is a precursor of glutathione, a strong antioxidant and an essential compound in detoxification. We talk more about glutathione below.

Regulation of Homocysteine 

For most cells, homocysteine can be:

  • Remethylated into methionine
  • Exported out of the cell

The liver is responsible for breaking down excess methionine and maintaining optimal homocysteine levels. Homocysteine levels are regulated by a set of enzymes including MTHFR.

High levels of methionine in the liver result in increased AdoMet. High AdoMet inhibits MTHFR and initiates the enzyme CBS activity leading to more cysteine production.

When methionine levels are low, homocysteine is conserved. It is then re-methylated back to methionine.

A defect in the methionine metabolism can also lead to elevated homocysteine levels. This is what happens in mutations of MTHFR.

How Often Should Homocysteine Levels Be Checked? 

It is best to check homocysteine levels for abnormalities. Like thyroid levels, normal homocysteine levels are not optimal levels. See the following for homocysteine levels:

  • HIGH Homocysteine: >15 µmol/L 
  • NORMAL Homocysteine: 4-15 µmol/L
  • OPTIMAL Homocysteine: 10-12 µmol/L

Folate, B6, and/or B12 may help lower homocysteine levels. Folate, B6, and/or B12 should be taken for two months. At that time check homocysteine levels to see if they have become optimal.

Homocysteine levels still elevated should have an increase in the vitamin dose. Then recheck homocysteine levels in another two months.

MTHFR Plays a Critical Role in Folate and DNA Metabolism

Folate metabolism needs methyltetrahydrofolate reductase (MTHFR).

The enzyme methionine synthase (MTR) can remethylate homocysteine. This enzyme links the folate cycle with homocysteine metabolism

MTR also requires cobalamin (B12) to activate a reaction resulting in the complex Cbl(I)MTR which binds the methyl group of 5-methyTHF (folate) to form methylcbl(III)MTR.

The enzyme methylenetetrahydrofolate reductase (MTHFR) is needed for recycling to be the most efficient.

Severe hyperhomocysteinemia (total homocysteine >50 uM) or homocystinuria is caused by defects in remethylation or transsulfuration.

Disturbed remethylation can be caused by MTHFR as well as MTR deficiency due to mutations in their genes. MTR can also be dysfunctional due to defects in cobalamin metabolism.

In MTR deficiency or dysfunction, 5-methyl THF cannot cycle through MTR resulting in 5-methyl THF accumulation at the expense of the other folates, hampering the synthesis of purines and thymidine.

In particular, rapidly dividing cells, such as bone marrow, will be affected and result in megaloblastic anemia and pancytopenia, which are also observed in folate deficiency.

MTHFR deficiency, on the other hand, does not limit the availability of folates for purines and thymidine syntheses and therefore shows no abnormalities in blood cells.

Remethylation defects result in elevated homocysteine and decreased methionine. In the transsulfuration pathway, CBS deficiency also results in the accumulation of homocysteine, but in contrast to remethylation defects, methionine is increased.

Folate Metabolism is Needed for DNA Methylation

Folate has a potential role in the DNA methylation process. DNA methylation can be a biomarker to assess folate status. It may be a link to disease outcomes. Also, folate’s role in 1-carbon metabolism related to DNA methylation and low folate status and DNA methylation will be explored.

Background of DNA methylation

DNA methylation is under tight control because undermethylation and over-methylation may result in tumors.  The depletion of folate may lead to undermethylation of DNA and therefore increase the risk of cancer. Repletion with folate may be more responsive to increasing DNA methylation in people with the MTHFR TT genotype than the CC genotype. 

Low folate may cause hypo- and hypermethylation. It can also result in dysregulation of DNA methylation. However, research at this time is still in its infancy in regards to the effects of folate supplementation and its effects on overall cancer risk.

Nutrients for optimal DNA methylation

In addition to folate, the following nutrients are needed for optimal DNA methylation: 

  • Vitamin B-6 (serine hydroxymethyltransferase activity) 
  • Riboflavin (MTHFR stability)
  • Vitamin B-12 (methionine synthase function)
  • Choline

Other factors that reduce DNA methylation

DNA methylation varies additionally with other factors including:

  • Gender (being female may reduce DNA methylation)
  • Aging
  • Environmental exposures
  • Air pollution
  • Benzene exposure
  • Estrogen replacement medication

All of the above results in a reduction in DNA methylation at various stages of life and is even thought to be reduced in utero due to toxin exposures

  • Avoid exposure to toxins
  • Optimize micronutrient status
  • Perhaps avoid synthetic estrogen

MTHFR Mutations, Variations and Polymorphisms

There is some confusion about the difference between mutations, variations, polymorphisms, and single nucleotide polymorphisms in MTHFR.  In a nutshell, all of these terms are referring to the same thing.  

MTHFR mutation, or variants,  in the genes coding for MTHFR are common. These mutations reduce the ability of the body to process homocysteine properly. They are also referred to as single nucleotide polymorphisms (SNP) affectionately referred to as “snips.” 

These MTHFR variants can lead to a buildup of high levels of homocysteine in the blood and decrease the levels of folate, B6, and B12 vitamins. 

MTHFR enzyme affects riboflavin metabolism as well.  


People with gene variants have a lower affinity for riboflavin, which can result in elevated homocysteine levels.

MTHFR Gene Mutations and Other Causes of MTHFR Compromise

MTHFR genes help control methylation in the body. People with MTHFR variants may have reduced functional capacity.  Genetic variations in the MTHFR enzyme gene results in reduced activity of the enzyme produced and are related to the following conditions:

  • Heavy metal detoxification
  • Cellular repair 
  • Production and repair of DNA and mRNA
  • Neurotransmitter production
  • Making methionine from homocysteine
  • Buildup of homocysteine
  • Antioxidant production, such as glutathione
  • Healthy immune system function
  • Formation and maturation of red blood cells, white blood cells, and platelet production
  • Neutralizing histamine
  • Autoimmune diseases
  • Making melatonin

As you can see, the function of the MTHFR gene is widespread.  With an MTHFR gene variant or mutation, a lot of processes in the body can be affected. 

Some people can’t eat foods with histamines due to this gene. It is known as histamine intolerance.  

A build-up of homocysteine in the body results in increased heart disease risk and diseases like thyroid disorders and increases susceptibility to autism. 

In addition, an MTHFR mutation can result in the build-up of medications in the body, causing toxic effects and adverse drug reactions. 

How Common are MTHFR Mutations?

Many individuals have a variant in the MTHFR gene, which means there is some amount of alteration in the DNA sequence that makes up that gene. 

Variants may occur in 40% of the Caucasian population. The overall risk imposed by most MTHFR variants appears to be small from the data we have so far. Mutation heterozygous MTHFR types are more common and also less severe.

Two common MTHFR variants or mutations include the following:

  • C677T
  • A1298C

Here is an overview of what each of these mutations means for health. 

The C677T Mutation

C677T, or MTHFR C677T (Rs1801133), mutation leads to elevations in total homocysteine levels in the blood. 

If people have a single A allele of C677T, there is a

  • 35% reduction in MTHFR actvity

For those with a double AA allele, there is a

  • 70 % decrease in MTHFR activity

Due to a decrease in enzyme activity, there is less ability for the body to make activated folate within the cell. Activated folate is called 5-methyl tetrahydrofolate.

The C677 gene variant is one of the most researched genes we have, yet experts still caution against a wide interpretation of it.

The A1298C Mutation

The A1298C mutation, or MTHFR A1298C (rs1801131), has a less severe reduction in MTHFR activity than C677T, which means there are fewer issues with homocysteine and folate abnormalities.

However, the A1298C mutations can be linked to mood disorders. This mutation is more likely to alter neurotransmitters.

People with this gene variant are also more likely to have autoimmune conditions and more adverse medication reactions as well.

And guess what? It is also possible to have both gene mutations. I do. 

Compound Genes

An example is this: if a parent passes along a C677T gene and your other parent passes along the A1298C gene, you have what is called a compound heterozygous gene pattern.  

There are differences among people with these genes. Some people have their gene activity reduced by 90 percent, while some are reduced by only 10 percent.

Which Mutation Affects Thyroid Function?

The methylation process repairs damaged cells. It also requires optimal protein for DNA cell function. 

Methylation is key to:

  • Metabolizing chemicals and toxins
  • Breaking down B-vitamins for hormones and neurotransmitters
  • Regulating dopamine, serotonin, norepinephrine which can influence sleep, behavior, and cognitive abilities

Dysfunction of MTHFR may cause thyroid disease. A healthy thyroid will have tightly regulated levels of MTHFR in the thyroid hormone thyroxine.

MTHFR helps to methylate and use B-vitamins and clear toxins, so there are pretty obvious reasons that variants in MTHFR can cause thyroid dysfunction. 

When thyroxine is low, the body is less able to convert riboflavin, a B-vitamin to form needed for MTHFR as well. 

The A1298 variant seems to be more related to hypothyroidism. 

For example, the AA allele, which is homozygous, and the AC allele, which is heterozygous, have the highest risk of hypothyroidism compared to C677T allele variants. 

However, research is somewhat limited at this time. It is only available in select populations.  There are some patterns emerging in research related to thyroid and MTHFR. 

When it comes to hypothyroidism, the A1298 variant plays a stronger role than C677T.  

For example, the AA allele variant of A1298 has the highest risk of hypothyroidism

  • AA (45.9%)
  • AC (37.8%)
  • CC (16.3%)

In regards to hyperthyroidism, there are no set MTHFR gene variants so far [R].

Other MTHFR Thyroid Connections

MTHFR C677T polymorphism is associated with thyroid cancer both in Caucasians and Asians. In a meta-analysis study of 5 research studies, including 2,554 cases and 2,671 controls.

The C677T variant appears to increase the risk of thyroid cancer by about 20 percent. 

Gene alterations MTHFR C677T may contribute to environmental susceptibility (epigenetic regulation). 

DNA methylation mediated by DNA methyltransferases may occur in patients with subclinical hypothyroidism. Additionally, carriers of the T allele might have an increased risk of developing subclinical hypothyroidism as well as thyroid cancer and breast cancer.

Tips for People Who Have MTHFR

Having a variant or mutation in the MTHFR gene requires that you are extra careful with

  • What foods you are exposed to
  • The quality of your water
  • The toxins in your environment.  

For example, exposure to lead, mercury, or bisphenol A can further worsen the methylation functions, cause even more build-up of homocysteine, and reduce protein and phospholipid production in the body

Here are some tips for those with MTHFR:

  • Drink filtered water
  • Eat mercury-safe fish 
  • Consider chlorella supplements 
  • Kick the chemical cleaners in your home to the curb  
  • Use only natural beauty products
  • Eat foods with natural folate
  • Boost your microbiome 
  • Consider n-acetylcysteine supplements for glutathione support 
  • Check your vitamin B12 levels
  • Take an all-natural multivitamin and mineral supplement
  • If at all possible avoid prescription drugs that interfere with nutrients, such as stomach acid medications, antibiotics, metformin, methyldopa, and methotrexate
  • Avoid cooking in plastics
  • Use glass containers instead of plastic for drinking
  • Eat organic to avoid chemicals and pesticides in foods 

MTHFR and Heart Disease

Serine hydroxymethyltransferase (cSHMTT polymorphism) is another gene involved in folate metabolism.

This gene is related to a very high risk of cardiovascular disease in men with over a 10 fold increase in heart disease risk over “normal” MTHFR genes [R].

Other Diseases Associated with MTHFR

Diseases associated with MTHFR genetic mutation or variation, including:

  • Autism
  • Down syndrome
  • Frequent and late term miscarriages
  • Infertility
  • Pulmonary embolism and other blood clots
  • Mood disorders, addiction, schizophrenia
  • Fibromyalgia and migraines
  • Chronic fatigue syndrome
  • Chemical sensitivity
  • Parkinson’s disease and stroke
  • Irritable bowel syndrome  
  • Spina bifida
  • Breast cancer
  • Alzheimer’s disease
  • Cardiovascular disease
  • Drug toxicity, including methotrexate and nitrous oxide
  • Autoimmune diseases 
  • Gastrointestinal issues

MTHFR gene variants are just a risk factor; having these variants does not necessarily mean you will get these conditions. It does, however, increase your odds of these.  

Keep in mind, other genes, such as the BRCA gene, also are risk factors for breast cancer too. 

MTHFR and Vaccines

MTHFR mutations may increase the risk of adverse reactions to vaccines. However, research on this topic is very limited. 

For example, in a study of vaccine-naive people, people who received smallpox vaccines with MTHFR mutations had a 2 to 4-fold increase in adverse reactions to the vaccine compared to people who did not have MTHFR mutations (wild type MTHFR).

However, MTHFR and other vaccines have never been explored in research.  Since smallpox vaccines are not administered anymore, no conclusions can be made from the research we have so far. 

Still, many toxins are administered when a vaccine is injected into your arms, such as formaldehyde, thiomersal (a form of mercury), preservatives, and antibiotics.

It makes sense to check antibody titers when possible before getting a vaccine if you have an MTHFR variant.

MTHFR & Autism

Our genes are affected by the foods and nutrients we eat.  This is because they have epigenetic effects, which means that compounds in foods and nutrients have the ability to modify a genetic expression.  

Neurodevelopmental disorders like autism, schizophrenia, Down, Rett. Fragile X syndromes, tuberous sclerosis, and neurofibromatosis conditions may be muted or reduced with the proper nutrition, according to a review paper in Neuropharmacology.

Autism is the most common neurodevelopmental disorder, so more research has been conducted to explore the links between MTHFR and autism.

MTHFR and autism are related.  For example, we know that MTHFR 677T allele is more common in autism.

One study found an almost 3-fold increased risk of getting autism with the MTHFR 677T variant.

The normal 1298AA allele, however, was more normal in children with autism, suggesting that not all variants increase the risk of autism.

Autistic-like behavior is linked to MTHFR actions related to prenatal nutrition.  For example, when mice were given MTHFR vitamins, they had fewer symptoms of autism than the mice who did not receive prenatal MTHFR vitamins.

Further, according to Dr. Raphael Kellman in a publication called Autism Parenting, she has noticed a high frequency of hypothyroidism in autistic children.  Symptoms of hypothyroidism and autism overlap somewhat as well. 

According to Dr. Ben Lynch, autism began to rise sharply after the fortification of foods with folic acid began in 1992.  While this is not necessarily causation, it is an interesting observation. More studies need to be conducted to determine if fortification of natural folate will reduce the risk of autism. 

In the meantime, if you have an MTHFR variant, it is best to supplement with prenatal MTHFR vitamins and MTHFR children’s vitamins for children rather than those containing folic acid.

MTHFR Treatment Weight Loss Connection

Having a variant in MTHFR, such as the C677T variant, increases the risk of obesity slightly and especially if also in conjunction with elevated homocysteine levels in a large population study.

Further, excess folic acid increased weight gain, and inflammation in mice fed a high-fat diet.

While we don’t know if adding in a natural form of folate, such as methylfolate, helps weight loss, there are many anecdotal reports of its benefits in helping manage weight for people with MTHFR mutations. 

MTHFR and Hypertension

The C677T gene variant is also linked to increases the risk of hypertension.

MTHFR and Anesthesia  

A compelling reason to know your MTHFR gene status is that exposure to some types of anesthesia, such as N2O or nitric oxide, increases the risk of complications during surgery. 

This is because N2O increases homocysteine during surgery, which may increase the risk of venous thrombosis, myocardial infarction, and stroke.

Several case reports of children undergoing anesthesia with nitric oxide use resulted in death.

Use of Sevoflurane and propofol anesthesia and intubation with rocuronium was safe in 24 children with MTHFR alleles.


If you have an MTHFR variant it is extra important that you pay attention to the foods you eat.  The most important thing to do is to avoid folic acid.  

Here are the reasons why. 

Folate is a natural vitamin called vitamin B9.  In contrast, folic acid is synthetic and is quite different in how the body handles it.  

Made in a lab, folic acid is different enough that if the body has MTHFR variants, it won’t convert well into the active form of folate in the body. 

Yet, research studies and the medical community often describe folate and folic acid as if they were the same. 

How to Avoid Folic Acid

Avoid enriched foods.  Enriched foods always have synthetic folic acid, so it is best to avoid them as much as possible. 

The words “enriched” on a food label indicates the grains have been stripped of their B vitamins and replaced with synthetic folic acid. 

The best way to avoid them is consuming true whole grains, preferably gluten-free.

Many processed foods contain enriched grains. Processed grains that are enriched include white flour, bread, protein bars, pasta,  crackers, cookies, chips, cakes, pies, white rice,  pretzels, donuts, and other highly processed foods and snacks. 

Instead, your clients with thyroid and MTHFR should opt for gluten-free, whole grains depending on their tolerance of grains. When possible, the grains should be sprouted and fermented. 

Eat Folate-Rich Foods 

Folate-rich foods are much better than folic acid in general because they are more easily converted to activated folate in the body and because they are also rich in nutrients that are good for the thyroid too. 

Examples of folate-rich foods include: 

  • Spinach
  • Kale
  • Broccoli
  • Romaine
  • Swiss chard
  • Pumpkin seeds
  • Avocado
  • Asparagus

When you take folate and B complex vitamin supplements, make sure they contain natural folate instead of folic acid too. This is indicated by the words “methylfolate.”

Should Other Foods Be Avoided?

MTHFR gene variants are also linked to digestive conditions like inflammatory bowel diseases, such as Crohn’s disease [R].

An autoimmune protocol diet may be beneficial in these cases. An MTHFR meal plan includes a gluten-free diet and avoiding inflammatory and processed foods. 

Glutathione MTHFR Connection

Methionine is required to make glutathione in the body.  With MTHFR mutation, there is less methylation, less cysteine production too.  This means the net result will be less glutathione production in the body.

Why Does Glutathione Matter?

Glutathione is a major antioxidant in the body that helps reduce inflammation in the body. 

To keep your glutathione levels optimal if you have an MTHFR mutation, make sure you get

  • Adequate B-vitamins (folate, vitamin B6, vitamin B12)
  • Protein-rich foods that contain cysteine, glycine, and glutamine 

Watch Out for Toxins and Heavy Metals

Having MTHFR makes you more susceptible to some toxins like mercury.

Interestingly, people who are sensitive to mercury toxicity may have an increased risk of autism in their offspring as well; a 1 in 22 chance of autism compared to 1 in 160 chance of autism in people not sensitive to mercury toxicity.

What helps the body remove mercury and other toxins?  


It is important for people with MTHFR to maximize their antioxidants, particularly glutathione.

With MTHFR variants, the body’s ability to remove other toxins is also probably impaired for this same reason. 

How to Support Glutathione

There are many foods you can eat to boost glutathione

Food sources of glutathione include:

  • Strawberries
  • Mushrooms
  • Avocados
  • Watermelon
  • Spinach
  • Okra
  • Cantaloupe
  • Grapefruit

Foods that boost glutathione production in the body because they are rich in sulfur include: 

  • Eggs
  • Meats
  • Garlic
  • Onions
  • Leeks
  • Chives
  • Broccoli
  • Brussels sprouts
  • Cabbage
  • Cauliflower 

Supplementing Sulfur 

Supplementing sulfur by taking N-acetylglucosamine, especially in the sublingual form, also helps the body produce more glutathione so that the body can remove toxic compounds.

Eat More Antioxidants

Another healthy way to promote detoxification in the body is to eat more antioxidants in general.  

How To Test For MTHFR

MTHFR testing can be done with any lab that tests for genetics. Testing can also be done via saliva or blood tests.

MTHFR Test Kit

Testing for MTHFR can be done in your practice or if you are working with clients virtually you can have them order a kit online. 

Aside from DNA test kits, there are saliva, blood, and specific MTHFR test kits available to choose from.

DNA Test Kits

DNA Tests will give you the exact genetic information you need to know if your client has an MTHFR mutation. 

If you go this route, you will need to download your client’s raw gene data and upload it to a gene interpreter website. There may be fees associated with these converters, such as those with

Two other websites are more affordable for gene interpretation: Found My Fitness and Promethease. Found My Fitness is only compatible with 23andMe DNA test kits and costs up to $25 for a comprehensive report. 

Promethease costs about $12 and is produced in less than 10 minutes. Full genomes will take longer and have an additional cost. They accommodate DNA from 23andMe,, FamilyTreeDNA, and others.

Self-Decode is another option with yearly membership and support.

23 and Me DNA Test Kit

A very popular DNA test kit is the health kit from 23andMe. Over 23 million people have tested their ancestry with at-home DNA kits, so it is not a big leap to check health data for most people.

23andMe is the only FDA-approved DNA testing kit. The only catch is that you will need to download your raw DNA data to find out your MTHFR status as stated above.

Check Price Here Test Kit

Much like 23andMe, provides a reasonably priced and highly rated gene test. You will still need to download your raw data to find out your MTHFR status.

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Self Decode DNA Test Kit

The Self Decode offers annual subscription or lifetime access for DNA Wellness Reports and also has DNA test kits.

It also has a program for practitioners offering discounted rates on DNA kits. 

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Vitagene DNA Test Kit

If you are looking for the most reasonably priced and easy-to-understand health data, Vitagene is the test for you or your clients. It gives you the MTHFR gene results under the folate section.

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MTHFR Specific Tests


Spectracell is a lab that offers various metabolic testing including MTHFR testing. Health providers can become partners with Spectracell at no cost. Learn more about the testing.

Walk-In Lab

Walk-In Lab offers a way to order MTHFR test kits online. They are sent via mail and then taken to the lab where the test will be done. You can also sign up as a provider and get a discount on testing prices.

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Life Extension

Life Extension is a health and vitamin company that offers a cheek swab MTHFR test. This cheek swab test can help determine if you have common variants of either gene. You can order to test and have done in your practice.

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Saliva Test for MTHFR

Saliva test kits can be as accurate as blood tests if they are collected properly.

The benefit of testing saliva DNA for MTHFR is that you can access a huge database of what makes your client, THEM. Saliva Test

MTHFR can be detected using a saliva test. This is a noninvasive option for someone looking to get information about MTHFR. One popular one is from

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RX Home Test Saliva

Test box for RXHome MTHFR Saliva Testing Kit | Thyroid Nutrition Educators

RX Home provides at-home saliva testing for MTFHR. It is an easy way to do MTHFR testing in your practice or have your patients do the testing from the comfort of their own home.

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Blood Test At The Doctor’s Office

Alternatively, you can have your client get their doctor to write a prescription for the MTHFR test.

Vitamin B12 and Thyroid Connection

A very large percentage of people with thyroid disorders also have low vitamin B12 levels.  This can affect MTHFR function too.  For example, 40% of people with hypothyroid also have vitamin B12 deficiency.

That is a lot of people suffering in silence!

If your client has a thyroid condition, you should also know their vitamin B12 status. 

“Normal” B12 levels are not always optimal levels. Those with normal levels between 200 and 350 pg/mL have been shown to have B12 deficiency symptoms. 

B12 experts like Sally Pacholok R.N. and Jeffery Stewart D.O., suggest treating all patients that are symptomatic when B12 levels are below 450 pg/mL.

They also recommend treating patients with the following markers:

  • Normal B12
  • Elevated urinary methylmalonic acid (MMA)
  • Elevated homocysteine and/or holotranscobalamin

MTHFR and Preterm Births

MTHFR gene deficits may also increase the risk of preterm births and miscarriages as well, especially the C677T polymorphism TT allele variant.  

Having this gene pattern increased the risk of preterm birth by 3 times according to the Journal of Clinical and Experimental Pathology.

Other research also confirms this link and finds that even the A/T variant increases the risk of preterm births.  

One variant of the MTHFR and miscarriages may also be protective in some people.  For example, the A1238 A/C MTHFR variant may be protective from preterm birth.

Research points to the fact that methylfolate is more effective than folic acid at raising red blood cell folate concentrations in all women.

Further, unmetabolized folic acid is found in the umbilical cords of babies whose mothers took folic acid.  Pregnant women who took natural folate were more effectively able to give folate to their fetuses than folic acid too.

It makes sense for pregnant women and breastfeeding women to choose methylfolate supplements instead of folic acid if they have any MTHFR variant. 

Even if you don’t know your gene pattern, choosing methylfolate is the safest form of folate in prenatal vitamins

MTHFR Prenatal Vitamin Recommendations

Thorne Research – Basic Prenatal – Folate Multivitamin

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Seeking Health Optimal Prenatal Chewable

Seeking Health Optimal Prenatal Chewable| Thyroid Nutrition Educators

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Best Folate Supplement for MTHFR

The form of folate that you will want to look for is typically designated as natural, but some supplements hide synthetic folic acid in their products! 

Make sure to read the ingredients from top to bottom to assure you don’t get folic acid. 

When buying folate supplements, you need to be very careful about looking for hidden synthetic folic acid.  

Supplements can look natural as can be and yet are far from it.  

Remember: people with MTHFR mutations are not able to convert folic acid to activated folate in the body. 

The usable forms of methyl folate with MTHFR mutations are: 

  • Methylfolate
  • L-Methylfolate calcium (refers to the calcium salt molecule it is attached to)
  • Metafolin 
  • Deplin
  • 5-MTHF 
  • L-5-MTHF 
  • Levomefolic acid
  • 5-methyltetrahydrofolate
  • (6S)-5-methyltetrahydrofolate
  • Quatrefolic
  • Calcium methylfolate

Using natural and activated forms of folate is safer.  Folic acid use increases the risk of many health conditions

More Resources on MTHFR

For further reading about MTHFR genes and how to support your unique needs, check out these books on MTHFR: 

Dirty Genes by Dr. Ben Lynch 

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MTHFR Cookbook and Meal Plans

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The H Factor Solution: Homocysteine, the Best Single Indicator of Whether You Are Likely to Live Long or Die, Young

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Introduction to MTHFR for Beginners

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MTHFR Gene Therapy Demystified: Crack Your Genetic Code to Better Health

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I’m a Mutant! Are You?: A Beginner’s Guide to Living with an MTHFR Mutation

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Keys 2 Basic Health: Proactive Strategies for Healthy Aging Especially for Those with MTHFR

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The 85% Solution

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You can help your clients carefully choose whole foods and eat a lot of leafy green vegetables if they have an MTHFR gene variant and a thyroid condition.  

Consider taking a multivitamin and mineral that has methylfolate in it and avoid taking folic acid supplements and eating folic acid-fortified foods

Support glutathione by consuming sulfur-rich foods like eggs, cruciferous vegetables, mushrooms, and fruits like strawberries and grapefruit. Consider supplementing n-acetylcysteine to help boost your glutathione levels. 

Avoid exposures to toxins by filtering your water, drinking out of glass vessels, skipping plastics wherever possible, and choosing organic foods whenever possible to reduce chemicals in your diet.  

Consider checking antibody titers before vaccination whenever possible and avoid any sources of mercury too. 

Chlorella helps naturally remove heavy metal toxins from the body, so consider adding this healthy algae supplement to your diet.

More Thyroid Nutrition Articles

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